Kamel MH et al. (2006) Rabbit antithymocyte globulin related decrease in platelet count reduced risk of pediatric renal transplant graft thrombosis. Pediatr Transplant 10: 816–821

Thrombosis is a major cause of early graft failure in pediatric kidney transplant recipients. Rabbit antithymocyte globulin (RATG), which lowers platelet count, is commonly used as induction immunotherapy and to treat steroid-resistant rejection. As platelets are an important factor in vascular thrombosis formation, Kamel et al. investigated whether RATG therapy reduces the risk of graft thrombosis in pediatric kidney transplant recipients.

The trial included 120 kidney transplantations performed in 95 patients (mean age at transplantation 12.4 years). Patients undergoing transplantation during the period 1986–1990 (n = 61) received ciclosporin, azathioprine and steroids as maintenance immunosuppression; those transplanted from 1991 to 1998 also received RATG on the day of transplantation and for 4–10 days after (n = 59).

Over a median follow-up of 8 years, thrombosis occurred in six grafts; all thromboses occurred in the non-RATG group (P = 0.028), despite a similar distribution of thrombotic risk factors between groups. The median drops in platelet count 1 and 3 days after transplantation were significantly greater in RATG-treated patients than in the non-RATG group (P ≤0.001 for both). Infection risks were similar in the two groups. Actuarial graft survival at 1, 3, 5 and 10 years was higher in RATG-treated patients than in those who had not received RATG (P = 0.014), but improved in the non-RATG group after exclusion of thrombotic events. Actuarial patient survival did not differ significantly between groups.

The authors conclude that RATG therapy early after transplantation might reduce the risk of graft thrombosis by decreasing platelet count.